Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 238	$ 124
Accounts receivable, net	137,607	124,222
Prepaid expenses and other	37,590	34,643
Total current assets	175,435	158,989
Property and Equipment, at cost	1,056,435	995,514
Less-accumulated depreciation	467,212	456,335
Net property and equipment	589,223	539,179
Goodwill and Identifiable Intangibles, net	26,649	26,986
Other Noncurrent Assets	4,398	4,039
Total assets	795,705	729,193
Current Liabilities:
Accounts payable	59,723	54,754
Wages, vacation and employees’ benefits	30,423	27,834
Other current liabilities	46,700	46,360
Current portion of long-term debt	13,659	12,432
Total current liabilities	150,505	141,380
Other Liabilities:
Long-term debt, less current portion	102,780	56,540
Deferred income taxes	69,078	67,417
Claims, insurance and other	34,574	35,967
Total other liabilities	$ 206,432	$ 159,924
Commitments and Contingencies
Stockholders’ Equity:
Preferred stock, $0.001 par value, 50,000 shares authorized, none issued and outstanding
Common stock, $0.001 par value, 50,000,000 shares authorized, 25,186,278 and 25,141,799 shares issued and outstanding at March 31, 2016 and December 31, 2015, respectively	$ 25	$ 25
Additional paid-in-capital	231,114	230,593
Deferred compensation trust, 174,171 and 165,971 shares of common stock at cost at March 31, 2016 and December 31, 2015, respectively	(3,319)	(3,102)
Retained earnings	210,948	200,373
Total stockholders’ equity	438,768	427,889
Total liabilities and stockholders’ equity	$ 795,705	$ 729,193